Multiple spring tester



1952 R. E. SCHAFER ET AL MULTIPLE SPRING TESTER Filed Nov. 24, 1950 rlll lmlw INVENTOR ROBERT E. SOHAFER MARLIN I. KREIDER 4 ATTORNEY Patented Oct. 21, 1952 MULTIPLE SPRING TESTER Robert E. Schafer, Lancaster, and Marlin I.

Kreidcr, Ephrata, Pa., assignors to Hamilton Watch Company, Lancaster, Pa.

Application November 24, 1950, Serial No. 137,368

4 Claims. (01. 73-91) I v This invention relates toan' apparatus for life testing a plurality of watch mainsprings.

The object of the invention is to provide'an apparatus upon which can be mounted a plurality of watch'mainsprings and which ina relatively short time will continually wind and unwind the springs to determine the working life of the spring.

A further object of the present invention is to provide an apparatus for testing the fatigue limit of coil springs, by alternately applying a winding and unwinding action to the springs for a predetermined period, simulating a length of working life of ten years or more.

A further object of the present invention is to provide an apparatus which will simultaneously test a plurality of springs and whichwill not be affected by the breaking of any of the springs but will continue to test the remaining springs, means being provided to record the point of failure of any one particular spring.

A still further object of the present invention is to provide an apparatus for fatigue testing watch mainsprings which will overv a period of approximately five hours give the springs a simulated ten year test. v p s A further object of the present invention is to provide an apparatus for. testing mainsprings which will test a plurality of springs simultaneously while said springs are mounted in the barrel in which they are to be usedin the watches.

The invention is illustrated in the accompanying drawing in which: 4

Figure 1 is a perspective view of the apparatus. v a

Figure 2 is a detail showin the driving mechanism.

Figure 3 shows an individual holding chuck for one of the springs.

Figure 4 shows the initial winding member for the springs.

Figure 5 is a detail view partly in section showing the means for fastening the cord to the disc. A base 9 supports an electric motor In having reduction gear box II, a driveshaft l2 carrying a pinion I3 which is in mesh with a large gear |4 supported by an upright plate l5. A stud I6 is carried by the large gear wheel I4 and pivwith a pinion l8 by a roller I9 mounted between a pair of levers 20 pivoted on the axle 2| of the pinion I8. The axle 2| is supported by upstanding plates 22 (only one of which is shown) and carries a plurality of discs 23. This is the description of conventional driving mechanism and except for supplying the motive power forms no part of the invention.

The discs 23 are formed with a peripheral groove 24 and are keyed to the axle 2| so that the driving pinion l8 will rotate the discs through 'otally supports a rack H, which is held in mesh 7 a complete, turn and reverse the direction of rotation for a second complete turn. This oscillation is imparted by motion of the rack H.

A platform 25 supports a plurality of cylindri cal chucks 26 which are mounted for rotation in ball bearings 21. This mounting is housed in a cylindrical casing 28 which is affixed to the platform 25. i

The cylindrical surface of each of the chucks 26 is helically grooved at 29 for the reception of a metallic cord 30, while its upper'surface is recessed at 3| to receive a mainspring barrel 32. Centrally located in the chuck and within the recess is a hardened pin 33 to supportthe arbor of the mainspring. This pin is securely fastened to the arbor and rotates therewith,serv ing as a thrust bearing or endstone for the rounded end of the mainspring arbor. The mainspring arbor is held stationary while the chuck and inserted pin 33 rotates. Three pinions 34 are set into the top of the chuck to engage the teeth 35 of the mainspring barrel, so that the barrel is held stationary with respect to. the chuck.

The cord 30 is provided with a hook 35 which is secured to the eye 31 in the'discs 23, so that movement of the discs in the direction of the arrow 38 will transmit the motion of the discs to the chuck 26. The reverse motion of the. discs 23 will not rewind the cord 30 on the chuck 26 but merely relieves the pull on the cord 30 and permits the wound spring through its unwinding wind the springs to a full wind position before attaching the cords to the oscillating discs. After the springs are manually wound by the handle 45, the pistons 4| are locked from rotation by tightening a split collar 46. Counters 41 adjacent each of the chucks keep an accurate record of the number of times the springs are wound.

In the initial setting the mainspring and its companion barrel and barrel arbor are placed in the circular recess 3| of the chuck, the teeth 48 of the mainspring barrel engaging the pinions 34 which are rigidly set in the chuck 26, thereby securely locking the barrel to the chuck. The

piston is moved vertically in the bearing 4|] until the square end 43 of the barrel arbor fits in the socket 42 of the piston.

Manual rotation of the 7 piston 4| by the handle 45 winds the spring to completev windposition and the piston is then looked inipositi'on by the split collair 1'5. At the same time'the cord which is completely unwound from the chuck is attached to the disc 23 by means of the hook 38 and the eye 31 at a time when the discs are in the position of .full wind of the spring. All this is done with the machine stationary for each of the springs. The motor is then started and the first revolution of the discs is in a direction counter to the arrow 38, the tension of the spring rotating the chuck T011 its bearings 21 to Wrap the cord 38 about the chuck constantly maintaining a slight tension on this cord. Further oscillation of the discs alternately winds and 'unwinds the :spring at a point from full wind to /3 unwind which "tests the spring as it ts -used in a watch. fhe mo'tor through its gears ill may be geared to run at any particular speed and it'has been found'running at ten revolutions 'per minute will produce a test of one hundred years of spring use in approximately fifty hours. If at any time during the *test 'one of the springs breaks, the rotation of the chuck 2'5 will, of course, cease and the individualcounter at that particular chuck will show the number o'f revolutions at the time of stoppage. The remaining springs, however, continue to be tested, the rewrapped cord dropping from its particular disc when relieved of the tension due to breakage of the spring.

What is claim-ed is: 1. A multiple mainspring tester com-prising -a base, a platform mounted on sa'i'd base, a plural- 'ity of chucks rotatably mounted on said platform for supporting and carrying the 'mainsprings to be tested, an arbor attached to the inner end of each 'mainspring, means engaging the arbors for an initial manual winding and a subsequent holding of'sai'd arbors, means connected to said chucks for alternately unwinding and winding said mainspr'ings, and means for recording the number of times each 'mainspring is wound and unwound.

2. h'muitiplemainspring tester comprising a base, ,a platform 'on said base, a plurality of hucks rotatably mounted on said platform for supporting andcarrying the 'majinsprings' to be tested, an arbor attached to the inner end of each mainspring, means engaging the arbors for an initial 'manual Winding and a subsequent holding of said arbors, aplural'ity of oscillating discs, a flexible means connecting each of said discswith :each of (said chucks lto alternately unwind and wind "said mainsprings,and Jmeans for recording the number :0: times the mainsprings are wound and unwound.

B. .A multiplelma'inspring tester comprising a base, apl'a'tform mounted on said 'base, a plurality of chucks mounted in ball bearings on said platform .for easy rotation, a separate counter associated each chuck for recording the number of oscillations of said chucks, a plurality of standards, each standard associated with a single chuck; a piston 'slidably and rotatably mounted in each standard, manual means 'for turning any one 'oT-said pistons, means for 100k.

vidual chuck.

ing said piston against rotary and vertical movement, aplurality of mainspringbarrelscarried in said chucks, said barrels beingicomrected to and housing the main'sp'ringsto be tested, an arbor carried on the inner end of each of said mainsprings, said arbors terminating in a square end projecting above said mainspring barrel, said longitudinal and rotatable pistons being formed with a square hole for engaging the square end ofs'ai'd arbor, a "set of pinions carried on each chuck "to receive "the winding gear of said mainspring :barrel and :50 hold said barrel stationary with regard to said chuck, a spiral groove formed in the outer surface of each chuck, a flexible cord attached at one end to the chuck and adapted to be housedwithin :said 'spira-l groove, a plurality "of discs .formed with peripheral grooves mounted for'oscil lation so that (each {disc is in line with the edge of each chuck, :means for oscillating said discs, the .free endiof saidflexible cord being attached within the peripheral groove of each o'f said di'ses, themovenrent of said discs in one direction rotating said chucks and winding said mainsprings about the :stationary arbors, movement of the discs in thepther direction releasing the tension on the cordsand permitting the mainsprings 'to unwind and rotate the chucks to rewind the flexible cord .in the spiral groove.

4. A 'inultiple imainspring tester comprising a base, a platform mounted on said :Jcase, 1a plus-abi'ty of chucks mounted in ball bearings on. said platform for easy rotation, a plurality :of mainspring Ibarrel's carrying the mainsprings to "be tested, each barrel :being "securely held in each of said chucks, a spiral groove formed in the .face of each of said chucks, :a flexible "cord wound around eac'h o-f said chucks and within said spiral groove, an arbor attached to the inner end of each mainsprin means engaging the arbors for initial manual winding and subsequent stationary holding of said arbors, a plurality ro'f discs each formed with a peripheral groove, means tor oscillating said discs, the *free sneer each of said cords being fastemad withint'he peripheral groove of each of "said discs, whereby n1over-neat of the discs in one direction will wind the mainsprings and movement in, the otherdirection will permit the torque of the mainspri-ngs to back wind the cord on the spiral groove of the chucks, anda separate counter associated with each chuck for recording the .number .ofoscillations of its "indi ROBERT REFERENCES cr mp 1 The following references are of record in the file .of this patent;

UNITED STATES PATENTS Wunderlich Nov. 26, 11940 

